How to make a sensitivity slider?

So I want to make a sensitivity slider, my game is an FPS so it needs to be for first person controller and I was it it accommodate both X and Y sensitivity in the same slider. I want the slider on the main menu in my options section, and I want it to carry over to the game so on the game scene you use the sensitivity you chose, (the slider is on the main menu scene). Also, I'm going to need to use player prefs to save it so the player does not need to re do it every time, but I have no idea how! I need help thanks :)